AIO-0207 trial The 0207 study from Germany was designed to explore the advantages and disadvantages of different maintenance treatment strategies after first-line effective induction therapy (6 months of fluorouracil (FP)/oxaliplatin/bevacizumab (Bev)) for mCRC – Bev/FP versus Bev monotherapy maintenance or no treatment. The study was a non-inferiority design with the primary endpoint of TFS (time to treatment strategy failure) and enrolled 472 patients, aiming to demonstrate that TFS with Bev maintenance or no treatment was non-inferior to Bev/FP maintenance, with an upper HR of 1.43 for non-inferiority. The results showed that the HR for TFS was 1.03 (95% CI: 0.81-1.31) for Bev versus Bev/FP. The non-inferiority endpoint was achieved; the HR for TFS was 1.27 (95% CI: 1.0-1.62) for no treatment versus Bev/FP, and the non-inferiority endpoint was not achieved. Data from this ESMO update also suggest that RAS status, oxaliplatin reduction, did not affect efficacy, but the study found that after the first progression of disease, the protocol’s scheduled oxaliplatin reintroduction was actually performed at a low rate in clinical care (37% overall), which may have partially influenced the study results. Based on AIO 0207, the investigators concluded that bevacizumab alone was non-inferior compared to the standard maintenance treatment modality of Bev/FP and could also be a maintenance modality, but no treatment could not be concluded to be non-inferior. From the perspective of clinical practice, maintenance therapy should also be individualized. For patients with slow disease progression and small tumor compliance, simple observation without treatment is not a lost strategy, while single agent maintenance of bevacizumab is debatable. Jiang Fengcai, Department of Oncology, Anhui Provincial Hospital MACRO-2 trial The MACRO-2 trial from Spain was designed to explore the efficacy of cetuximab (Cet) ± mFOLFOX6 as maintenance therapy for mCRC. 193 patients with KRAS wild-type mCRC, receiving 8 weeks of mFOLFOX6 + Cet chemotherapy were randomized in a 2:1 group, with Cet maintenance therapy in the trial group , and the control group continued mFOLFOX6+Cet continuation therapy until progression. The trial was a non-inferiority design with the primary endpoint of the proportion of patients free of disease progression at 9 months, hypothetically 47% in the trial group and 62% in the control group, with final results of 63.8% versus 71.9%, OR=0.68, 95% CI 0.36-1.31, p=0.26, respectively, and the non-inferiority endpoint achieved. pFS was 8.9 versus 9.8 months, HR=0.69, 95% CI :0.45-1.06, p=0.09. OS was 23.6 versus 22.2 months,p=0.54. Cet maintenance treatment significantly reduced neurotoxicity (degree 3/4, 1.6% versus 14.5%). In fact, perhaps because of neurotoxicity, the cumulative dose difference between the last two groups of oxaliplatin was not so great (543.9 versus 645 mg/m2), whereas the cumulative dose of Cet was significantly higher in the Cet group than in the control group (5779.8 versus 4421.5 mg/m2), suggesting a significant dose of oxaliplatin and Cet in the FOLFOX6+Cet control group after randomization reduction. It is concluded that Cet monotherapy may be an effective maintenance therapy after mFOLFOX6+Cet induction therapy. information on RAS is also unpublished. This study provides for the first time the feasibility of Cet monotherapy for maintenance treatment and is worth exploring. The discussant Prof. Grothey summarized the above three studies by emphasizing that with the increasingly long OS of mCRC, the concept of using low-toxic and effective maintenance therapy has gradually become more widely accepted, and currently bevacizumab + fluorouracil should be the standard model of maintenance therapy, while the value of drugs such as erlotinib and cetuximab in maintenance therapy deserves further exploration. Although he believes that fluorouracil monotherapy should not be considered the ideal model for maintenance therapy (because capecitabine + Bev was significantly better than capecitabine monotherapy in the elderly study AVEX), considering the practical issues of cost-benefit and pharmacoeconomics, the author personally believes that it is still important and relevant to study the value of fluorouracil monotherapy as a maintenance therapy for mCRC. Of course, as Grothey emphasized, there are still many unresolved issues for maintenance therapy: how to screen the best suitable population? What is the optimal time frame for induction chemotherapy, and what is the minimal OS benefit?